[webkit-changes] [WebKit/WebKit] 783df4: [Multicolumn] Guard against zero or negative space...

[Ahmad Saleem]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 783df4eb909643460092a0df2e44bb5d1fe8fe5d
      https://github.com/WebKit/WebKit/commit/783df4eb909643460092a0df2e44bb5d1fe8fe5d
  Author: Ahmad Saleem <ahmad.saleem792+github at gmail.com>
  Date:   2023-01-08 (Sun, 08 Jan 2023)

  Changed paths:
    A LayoutTests/fast/multicol/widows-expected.txt
    A LayoutTests/fast/multicol/widows.html
    A LayoutTests/fast/multicol/widows2-expected.txt
    A LayoutTests/fast/multicol/widows2.html
    M Source/WebCore/rendering/RenderMultiColumnFlow.cpp

  Log Message:
  -----------
  [Multicolumn] Guard against zero or negative space shortage

[Multicolumn] Guard against zero or negative space shortage
https://bugs.webkit.org/show_bug.cgi?id=250282

Reviewed by Alan Baradlay.

Merge - https://src.chromium.org/viewvc/blink?view=revision&revision=174088

We need positive values in order to get anywhere when stretching columns
in order to balance them, and we may get called with zero or negative
values when there's zero-height content at column boundaries, so we
set an early break in order to honor widows in the next column.

* Source/WebCore/rendering/RenderMultiColumnFlow.cpp:
(RenderMultiColumnFlow::initialLogicalWidth): Add early return for "spaceShortage" to get positive values
* LayoutTests/fast/multicol/windows.html: Add Test Case
* LayoutTests/fast/multicol/windows2.html: Ditto
* LayoutTests/fast/multicol/windows-expected.txt: Add Test Case Expectation
* LayoutTests/fast/multicol/windows2-expected.txt: Ditto

Canonical link: https://commits.webkit.org/258647@main